How to be a country casual

It is no good waiting for the postman. The invitation will not come by mail. Madonna or Stella or Aurelia will telephone you. It will be a casual request along the lines of: "Why don't you come down for the weekend of the 23rd? We've got a couple of people staying over."

It will be followed by an e-mail with instructions on how to get there. ("Left onto the B7239. Right fork after 7.3 miles. Left at the sign to Long Sodbury. Left again 200 yards before the Dog and Duck and it's second on the right after the broken stile. You can't miss it.")

The country weekend is the new vogue. In the past few months, leading figures from the fashion set, including Madonna and Guy, Stella McCartney and Aurelia Cecil - the posh PR doyenne for the likes of Versace and Jaguar - have bought large houses in the shires and are giving weekend house parties.

They are following in a long tradition by the monied classes of living in town during the week and spending the weekend at their retreats in the sticks. And an invitation to join them for a couple of days of overeating, heavy drinking and hearty walks puts any London stiffy into the shade.

However, while it is easy to know the form for a smart London party (bung on something black, always take a liberal view, except on private schools, and don't Bogart the cocaine), weekend manners are an altogether trickier matter.

House presents

A Cellophane bunch of chrysanthemums from the motorway service station is not acceptable. Nor will you be thanked for something from a London supermarket or deli. They now have supermarkets in the country and your host will proclaim loudly that the local organic farm produce is better than anywhere else.

Acceptable presents are smellies, very good chocolate, caviar, decent champagne and expensive jokes (a HermËs dog whistle, for example, or a silver Tiffany tennis-ball holder). The coffee-table book of Great English Country Houses is not popular. If the host's mansion is in the book, they already have a copy and if it isn't, they don't want it.

Dress

Annoyingly, your host and hostess will have an extensive wardrobe with which you must compete from your weekend bag. Their smart/casual evening clothes will be very smart (usually involving much cashmere) and their daytime clothes will be considerably more scruffy. Do not try to out-do them in the dressing-like-a-yokel stakes. On Friday evening your city clothes will be fine.

The following night you will probably get away with what is known outside the M25 as the "Hampshire code" - velvet jacket, open-necked shirt, smart jeans and slippers. During the day, design-free corduroys, a dull sweater and an ancient wax jacket will pass muster. Always keep a pair of gumboots in the back of the car. Gumboots are to the countryside what Gucci loafers are to town. And bring a dressing gown. Bathrooms are always sited miles from bedrooms.

Servants

All modern country hosts pretend they don't have servants but most have lots of people who "help out" or "do a bit of driving/cleaning/ gardening" etc. They must be treated with reverence. The queen of the staff is "The Daily" who, for £5.50 an hour, flicks a duster and occasionally irons. Despite the fact that your host and hostess are richer than Bill Gates, they are mean when it comes to wages. It is therefore imperative to leave a tenner in the bedroom for the cleaner, who will now be able to feed her starving children.

Conversation

Everyone in the countryside knows that Blair is a class traitor who plans to concrete over every sward from Hampshire to Hampstead Heath. Therefore, politics is best avoided. Also off the agenda are blood sports, foot and mouth, immigration, the price of lamb, the euro and the Beckhams - unless you hold extremely Right-wing views, in which case they are popular topics for heated agreement. Safe topics include the general wonderfulness of the locals, the ignorance of metropolitan foodies, the new Range Rover (for and against) and anything in Hello magazine.

Sunday morning

Bring your own hangover cure. There is no worse crime than stealing the last Alka Seltzer. Do not get up early and make your own breakfast. Breakfast is a communal meal provided by staff and held in silence. Do not take away the Sunday colour supplements, business sections or the News of the World to peruse during your morning ablutions. It is important to go for a walk. On the other hand, it is acceptable (although a bit racy) to slip into the Dog and Duck during the walk for a swift pint.

And finally...

Time spent in reconnaissance is seldom wasted. There is a legendary tale of the guest who was so well-oiled when he went to bed on Saturday night at a Yorkshire mansion that when he woke at four in the morning he had no idea where the bathroom was. In desperation he crept down the grand staircase and when he stumbled across a majolica urn at the bottom of the stairs he sat upon it with blessed relief.

The next day, despite the faintest of smells, he left unchallenged with the rest of the large house party believing he had got away with his nocturnal droppings. But back in London on the Monday morning he received a one-line fax at his office from his host. It said simply: "We know you did it, but where is it?"